2-Tetralin-1-yl-4,5-dihydro-1H-imidazole hydrochloride

Chemical Properties

Off-White Solid

Originator

Tyzine,Pfizer,US,1954

Uses

An alpha agonist, causing constriction of conjunctival blood vessels. Used in over-the-counter eye drops, this compound relieves the redness left by ocular irritants.

Uses

adrenergic agonist, nasal decongestant

Uses

2-Tetralin-1-yl-4,5-dihydro-1H-imidazole hydrochloride is an alpha agonist, causing constriction of conjunctival blood vessels,it is used in over-the-counter eye drops, this compound relieves the redness left by ocular irritants.

Definition

ChEBI: Tetrahydrozoline hydrochloride is the hydrochloride salt of tetryzoline. It is used as a nasal decongestant. It has a role as a sympathomimetic agent, a vasoconstrictor agent and a nasal decongestant. It contains a tetryzoline(1+).

Manufacturing Process

A mixture of 540 grams (9.0 mols) of ethylenediamine, 270 grams (1.53 mols) of 1,2,3,4tetrahydro-α-naphthoic acid, and 360 ml (4.32 mols) of concentrated hydrochloric acid was introduced into a two-liter, three-necked flask fitted with a thermometer, stirrer, and distillation takeoff. The mixture was distilled under a pressure of about 20 mm of mercury absolute until the temperature rose to 210°C. Thereafter, heating was continued under atmospheric pressure and when the temperature reached about 260°C, an exothermic reaction was initiated. The heat was then adjusted to maintain a reaction temperature of 275° to 280°C for 45 minutes and the mixture thereafter cooled to room temperature.
900 ml of 4 N hydrochloric acid was added and the aqueous layer stirred with warming until a clear, brown solution resulted. This brown solution was made strongly alkaline with sodium hydroxide. The oil that separated solidified and was collected on a filter leaving filtrate A. The solid was dissolved in 370 ml of alcohol with warming, and the solution was treated with 130 ml of concentrated hydrochloric acid with stirring and cooling. This acidified mixture was diluted with 300 ml of ether and chilled. The solid salt was collected and dried and the filtrate concentrated to approximately 300 ml, diluted with 300 ml of ether and the salt which separated collected and dried.
Filtrate A was extracted with ether, dried, acidified with alcoholic hydrogen chloride, and the salt which separated was collected and dried. There was thus obtained, when all the salt had been combined, 250 grams (69.3% of the theoretical yield) of 2-(1,2,3,4-tetrahydro-1-naphthyl)imidazoline hydrochloride, melting at 256° to 257°C.

brand name

Tetryzo- line is INN and BAN; Tetryzoline Hydrochloride is JAN; Tetrahydrozoline Nitrate is JAN.

Therapeutic Function

Nasal decongestant, Pharmaceutic aid

Biological Activity

Tetrahydrozoline is an α-adrenergic agonist and an imidazoline derivative. It plays a crucial role in the constriction of conjunctival blood vessels. Tetrahydrozoline is a common component of nasal and eye drop formulations.